I think you should focus on composition rather than on trying to define the difference between a picture and a photograph which is vague and open to considerable argument. Is that really necessary?

I would focus more on a discussion of the use of light, shadow, texture and shape in color and monochrome images, as well as the general 'rules' of composition which are a useful starting point in composing a visually interesting image.

Keep it as simple and practical as possible with concrete examples that clearly delineate the points you're trying to get across. I would avoid vague and amorphous definitions that may ultimately cause more confusion than clarity for young inexperienced minds.

For some reason, people think it's necessary to make changes where making a change results in less precise communication.

Phone number: (209) 482-8516 - as opposed to 209.482.8516. The first string of numbers is obviously a phone number. The last string could be anything. That makes communication less precise.

Writing a software program used to be called "programming." Now, it's called "coding." If you work in the coding department of the military, I doubt you would be writing software. "Writing code" suggests you are writing a way to send a secret message, not programming a game.

There are lots of other examples, but I'm not going to list anymore. Although, I will comment on the unnecessary practice of swapping nouns for verbs, as in "quote" rather than "quotation," "mix" instead of "mixture," and many more.

Not really related is the practice of substituting "image" for photograph," which has twice as many letters and another syllable. "Photo" never really seemed to catch on as a "professional" term.